draw animated bezier

[negrito]

hello jack

 

i've got a question that sure pops up quite often but i couldn't find any post in the forum.

 

well, it's about animated beziers. let's suppose i create a simple tween with a bezier like that:

 

TweenMax.to(mc, 3, {bezier:[{x:100, y:200}, {x:0, y:400}], ease:Expo.easeOut});

 

now this will tween my movie clip along the bezier. that's quite nice but i would like to draw the bezier the movieclip has tweened through. and this while it is tweening. of course i could make an onUpdate and draw tiny lineTo chunks at every enterFrame but the line can become edgy if i tween fast and with a low number of frames.

 

is there any possibility draw the bezier (curve) while it is tweening?

 

basically it's this behaviour but with curves: http://www.edwardporter.com/flash/Comp1.mov

[GreenSock]

Yeah, that behavior is easy with straight lines, but ones you introduce Beziers, it gets MUCH more complex. Flash's drawing API requires certain info to draw a curve and you'd essentially have to reconfigure the end point(s) and control point(s) on the fly and make the curve still follow precisely the same path throughout the tween. Not simple. So I don't have an easy answer for you. I may create a class eventually that'll make this easier, but in the mean time, the only thing I can think of is to use an onUpdate like you said. But you could wrap that functionality into a class of your own whose setter has logic in it that checks to see how far the new point is from the last one and if it's too far, it breaks it into smaller chunks and follows the Bezier curve accordingly. That way, you don't get the choppy parts when the tween goes too fast.

 

Hope that helps a little at least.

[negrito]

thanks for the reply. i thought that there wouldn't be an easy way to do this but thanks for sharing your thoughts on it. if i found a nice solution i will post the code back here.

[negrito]

check out the following link if you want to create the effect shown in the video of my first post.

 

viewtopic.php?f=1&t=287&hilit=target+onUpdate